Sistema Nohoch Nah Chich is a cave system connected to the Caribbean Sea via a coastal spring called either Casa Cenote (for the restaurant located nearby), Cenote Manati, or Cenote Tankah. The explored cave system extends approximately 5 mi (8 km) inland from the coast. It is situated 10.3 mi (16.5 km) south of Quintana Roo, Mexico. Exploration of the cave commenced in 1987 from the cenote, Nohoch Nah Chich. Annual cave explorations are done by the CEDAM cave diving team, while a number of cave research efforts, in the fields of karst hydrogeology, water chemistry, microbiology, ecology, and archeology, were logistically supported. The technique of establishing jungle exploration camps at newly found cenotes and cave entrances was developed and refined during many cave exploration projects, thus making the cave diving exploration at the edges of the known cave more efficient. The main camp of exploration became Cenote "Far Point Station", located 6 kilometers (3.7 mi) from the coast, and 2.8 kilometers (1.7 mi) further inland than Main Base Camp situated at the main Nohoch Nah Chich Cenote entrance. In 1997, the Nohoch expedition expanded the total explored passage mark to 37 mi (60 km). By 2007 when it was connected into and included into the Sistema Sac Actun, the Sistema Nohoch Nah Chich included 36 cenotes and a recorded length of 42 mi (67 km). This portion of the system is now called the "Nohoch Nah Chich Historical section", where with 235 ft (71.6 m) also the greatest depth of the entire system was reached at "The Blue Abyss".